Isolation type prefabricated branch cable

Abstract

The utility model discloses an isolated prefabricated branch cable, which comprises a main cable and a branch cable, one end of the branch cable is connected with a conductor contact of the main cable, and a C-shaped crimping buckle is sleeved on the outer side of the conductor contact after connection; the box-type connector sleeves the outer sides of the branch cable and the main cable, the box-type connector is of a split structure and is formed by mutually buckling a first shell and a second shell, one end of the box-type connector is provided with a main cable inlet, and the other end of the box-type connector is provided with a main cable outlet and a branch cable outlet. According to the prefabricated branch cable, the box-type connector is arranged at the conductor contact position, the internal connection of the installed prefabricated branch connector is firm, the whole prefabricated branch connector is fireproof and sealed, and the appearance is smooth. The main cable inlet is sleeved with the convex clamping head, the concave groove is formed in the position of the main cable inlet, and after meshing, the phenomenon that the cable droops due to the dead weight, and the branch cable is connected easily to be separated can be prevented.

Description

Technical Field

[0001] The utility model belongs to the field of fireproof cables, in particular to an isolated prefabricated branch cable. Background Art

[0002] The isolated mineral insulated cable has strong fire resistance and complies with BS 6387 standards. Specifically, it can withstand continuous power supply for 180 minutes under a 950°C flame without breakdown, withstand water spray for 15 minutes after 150 minutes under a 650°C flame without breakdown, and withstand knocking and vibration for 15 minutes under a 950°C flame without breakdown.

[0003] With the increasing fire protection requirements for high-rise buildings and cables, the branch cables that need to connect the power distribution network of power equipment are developing rapidly. The isolated flexible mineral insulated prefabricated branch fire-resistant cable is a pre-branched cable that maintains fire resistance and is expanded on the basis of the isolated mineral insulated cable. Most of the existing branch cables use branch connection boxes or plastic injection molded connector branch cables. The defect of the former branch connection box is that it is not fireproof when encountering fire and is not waterproof when encountering water vapor, which poses an unsafe hazard to cable operation; the latter plastic injection molded branch connector can still maintain waterproofness at room temperature, but the performance of plastic has the characteristics of poor heat resistance, easy to burn, and easy to age, which affects the fire resistance of the cable. Therefore, neither the branch connection box nor the plastic injection molded connector method meets the BS 6387 standard that the isolated mineral insulated prefabricated branch fire-resistant cable should have. Utility Model Content

[0004] In order to make up for the deficiencies of the prior art, the utility model provides a technical solution for installing an isolated prefabricated branch cable of a prefabricated branch connection section by using a box-type connector.

[0005] The isolated prefabricated branch cable comprises a main cable and a branch cable, one end of the branch cable is connected to the conductor contact of the main cable, and after the connection, a C-shaped crimping buckle is sleeved on the outer side of the conductor contact;

[0006] It also includes a box-type connector, which is sleeved on the outside of the branch cable and the main cable, and the box-type connector is a split structure, consisting of a first shell and a second shell that are interlocked with each other, a main cable inlet is arranged at one end of the box-type connector, and a main cable outlet and a branch cable outlet are arranged at the other end, the main cable includes a main cable inlet and a main cable outlet, the main cable inlet is arranged in the main cable inlet, and the main cable outlet and the branch cable are arranged at the main cable outlet and the branch cable outlet respectively.

[0007] Furthermore, a groove is arranged on the edge of the first shell, and a ridge is arranged on the second shell. The ridge is arranged corresponding to the groove, and the ridge is inserted into the groove when the first shell and the second shell are buckled.

[0008] Furthermore, after the first shell and the second shell are buckled together, a high temperature resistant sealant is applied to the joint.

[0009] Furthermore, fixing screw holes are provided on the inner wall edges of the first shell and the second shell, and the first shell and the second shell are fastened together and locked by bolts.

[0010] Furthermore, the fixing screw hole includes an unthreaded boring hole arranged on the first shell and a fine threaded hole arranged on the second shell, the unthreaded boring hole and the fine threaded hole correspond to each other, and the bolt passes through the unthreaded boring hole from outside to inside and is screwed into the fine threaded hole.

[0011] Furthermore, 7 unthreaded boring holes and 7 fine threaded holes are provided respectively, and the fine threaded holes are distributed in a 2-2-3 pattern from the line inlet to the line outlet.

[0012] Furthermore, the bolt is a hexagon socket head screw.

[0013] Furthermore, a concave groove is arranged on the inner wall of the main cable inlet, and a convex clamp is arranged on the main cable inlet, and the convex clamp is clamped in the concave groove.

[0014] Furthermore, the main cable and the branch cable are composed of a twisted copper conductor, a mica tape insulation layer, an aluminum metal sheath, a toothed fireproof isolation sheath, a fireproof layer, a fireproof sheath and a halogen-free low-smoke outer sheath from the inside to the outside.

[0015] Furthermore, two layers of mica tape and two layers of non-woven fabric are cross-wound around the outer side of the conductor contact, and are coated with a functional hot-melt sealant, which is baked by a blowtorch to shrink it to form an inner sealing package.

[0016] Compared with the prior art, the utility model has the following advantages:

[0017] The present application prefabricated branch cable has a box-type connector at the conductor contact point. The box-type connector is buckled by grooves and ridges and locked by bolts and fixing screw holes. After installation, the pre-branch connector has a firm internal connection, an overall fireproof seal and a smooth appearance.

[0018] The main cable inlet is provided with a convex clamp and a concave groove is provided at the main cable inlet, which forms a good sealing effect after assembly. In addition, due to the function of the engagement device, the cable can be prevented from sagging due to its own weight, and the branch cable connection can be easily separated. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of prefabricated branch cables;

[0020] Figure 2 This is a schematic diagram of the prefabricated branch cable connection end;

[0021] Figure 3 This is a cross-sectional diagram of the main cable and branch cables;

[0022] Figure 4 It is a schematic diagram of the structure of the first shell of the box-type connector;

[0023] Figure 5 It is a schematic diagram of the second shell structure of the box-type connector.

[0024] In the figure: 1 stranded copper conductor; 2 mica tape insulation layer; 3 aluminum metal sleeve; 4 toothed fireproof isolation sleeve; 5 fireproof layer; 6 fireproof wrapping layer; 7 halogen-free low-smoke outer sheath; 8 main cable inlet; 9 main cable outlet; 10 branch cable; 11 conductor contact; 12 main cable inlet; 13 C-shaped crimping buckle; 14 concave groove; 15 convex clamp; 16 main cable outlet; 17 branch cable outlet; 18 groove; 19 convex ridge; 20 fixing screw hole. DETAILED DESCRIPTION

[0025] The utility model will be further described below in conjunction with the accompanying drawings.

[0026] like Figure 1 As shown, an isolated prefabricated branch cable includes a main cable and a branch cable 10. One end of the branch cable 10 is connected to the conductor contact 11 of the main cable. After the connection, a C-shaped crimping buckle 13 is sleeved on the outside of the conductor contact 11. A box-type connector is provided on the cable. The box-type connector is sleeved on the outside of the branch cable 10 and the main cable. The box-type connector is a split structure, which is composed of a first shell and a second shell that are mutually buckled. A main cable inlet 12 is provided at one end of the box-type connector, and a main cable outlet 16 and a branch cable outlet 17 are provided at the other end. The main cable includes a main cable inlet 8 and a main cable outlet 9. The main cable inlet 8 is provided in the main cable inlet 12, and the main cable outlet 9 and the branch cable 10 are provided at the main cable outlet 16 and the branch cable outlet 17, respectively.

[0027] Combination Figure 1-5 A groove 18 is provided on the edge of the first shell, and a convex rib 19 is provided on the second shell. The convex rib 19 is provided corresponding to the groove 18. When the first shell and the second shell are buckled, the convex rib 19 is inserted into the groove 18. After the first shell and the second shell are buckled, a high-temperature resistant sealant is applied to the joint. The inner wall edges of the first shell and the second shell are provided with fixing screw holes 20. After the first shell and the second shell are buckled, they are locked by bolts. In addition, a concave groove 14 is provided on the inner wall of the main cable inlet 12, and a convex clamp 15 is provided on the main cable inlet 8. The convex clamp 15 is clamped in the concave groove 14.

[0028] Continue to refer to Figure 4 and Figure 5The fixing screw hole 20 includes a non-threaded boring hole set on the first shell and a fine threaded hole set on the second shell. The non-threaded boring hole and the fine threaded hole correspond to each other. The bolt passes through the non-threaded boring hole from the outside to the inside and is screwed with the fine threaded hole. There are 7 non-threaded boring holes and 7 fine threaded holes respectively. The fine threaded holes are distributed in 2-2-3 from the inlet to the outlet. Specifically, two fixing screw holes 20 are set on both sides of the main cable inlet, and 3 fixing screw holes are set on the sides of the main cable outlet 16 and the branch cable outlet 17 at the other end. The other two fixing screw holes 20 are set on both sides of the box-type connector. In addition, the bolt is a hexagon socket head screw. Specifically, the 7 fixing screw holes on the first shell are non-threaded boring holes. Because the edge of the box-type connector has limited space, the main function of the connection is to seal the connection. Therefore, a fine threaded hole is set on the other half of the arc-shaped second shell wall tube. The helical rise angle is small, which can achieve a good effect of locking or preventing loosening after back locking, and the self-locking requirement is high. The bolts are made of stainless steel SUS202 hexagon socket head screws to prevent rust and are not easy to disassemble. The cylindrical head is buried in the box body, similar to the countersunk screws. The nail head is buried in the box body, and the connection strength is relatively large. The corresponding specifications of the hexagonal wrench are used to install and remove the screws. The nominal tensile strength of the bolt material reaches 1000MPa, the yield strength ratio of the bolt material is 0.9, and the nominal yield strength of the bolt material reaches 1000×0.9=900MPa. After the installation, the pre-branch connection body has a firm internal connection, an overall fireproof seal, and a smooth appearance.

[0029] Continue to refer Figure 3 The main cable 9 is composed of a stranded copper conductor 1, a mica tape insulation layer 2, an aluminum metal sheath 3, a toothed fireproof isolation sheath 4, a fireproof layer 5, a fireproof burn-proof sheath 6 and a halogen-free low-smoke outer sheath 7 from the inside to the outside. Similarly, the branch cable 10 is composed of a stranded copper conductor 1, a mica tape insulation layer 2, an aluminum metal sheath 3, a toothed fireproof isolation sheath 4, a fireproof layer 5, a fireproof burn-proof sheath 6 and a halogen-free low-smoke outer sheath 7 from the inside to the outside. A yellow wax tube is provided on the two sets of mica tape insulation layers of the branch cable 10. The yellow wax tube (UHMW-PE) is glass fiber, which is formed by drawing, weaving, adding insulating varnish, and then using a Ziegler-type high-efficiency catalyst 15-30pa low-pressure synthesis method. Ziegler-Natta polymerization is carried out under the catalytic conditions of organic compounds. It has linear molecules and very long molecular chains. The molecular weight is above 1.5 million to 3 million. Considering the thermal degradation of the molecules in the processing process, it has a high density with a viscosity-average molecular weight greater than 1.7 million. It is an ultra-high molecular weight thermoplastic engineering plastic with the highest values ​​of impact resistance, low temperature resistance, wear resistance, chemical corrosion resistance, self-lubrication, and impact energy absorption.

[0030] A more preferred embodiment is to insert cable paper into the stranded copper conductor 1 and the mica tape insulation layer 2 to protect the insulation seal of the conductor core, prevent moisture from entering, and avoid damage to the insulation layer. The insulation paper is made of unbleached sulphate softwood pulp, which is free-beaten without sizing or filler, and is made on a fourdrinier paper machine. The basis weight is 45-175 g / m 2 The paper is tough and uniform, has high tensile, folding and tearing strength, does not contain metal, sand or conductive acidic substances, has a high dielectric constant and low power factor, and has good stability when treated with insulating liquids.

[0031] During the production process, firstly, a special cutter is used to remove the halogen-free low-smoke outer sheath 7, fireproof wrapping layer 6, fireproof layer 5, toothed fireproof isolation sleeve 4, and mica tape insulation layer layer by layer 2 on the main cable, and the aluminum metal sleeve 3 is cut with a saw, leaving 30mm of length at the halogen-free low-smoke outer sheath 7, and the rest of the stranded copper conductor 1 is exposed, generally about 50mm in length, depending on the size of the branch connector of the cable specification. One end of the branch cable 10 is also removed layer by layer as described above, exposing the stranded copper conductor 1, generally about 50mm in length. Then the box connector is buckled on the outside of the conductor contact 11.

[0032] The corresponding strands of the twisted copper conductor 1 are put into a line, inserted into a copper C-shaped crimping buckle 13 of corresponding specifications, and loaded into a press mold. The C-shaped crimping buckle 13 is pressed by the press pressure, and the C-shaped opening is closed under the pressure. The inner side of the mold is designed with concave and convex ridges. The copper material of the C-shaped crimping buckle 13 has the characteristics of good softness and ductility. The main cable 9 and the branch cable 10 are tightly bite-jointed under the good plasticity of copper by the crimping force.

[0033] Two layers of mica tape and two layers of non-woven fabric are cross-wound around the conductor joint 11, and then covered with functional hot-melt sealant, and baked with a blowtorch to shrink it to form an inner layer of sealing package. The hot-melt sealant has a melting viscosity of 8000CPs / 180℃, a softening point of 85℃±<5℃, an initial viscosity>20# copper ball, a peel strength>4.3N / m, a melting temperature of 60-180℃, and has anti-oxidation, anti-halogen, acid and alkali resistance and plasticization.

[0034] The connected prefabricated branch connection section cable is installed into the semi-arc box-type connecting body, and the main cable inlet 8, the main cable outlet 9 and the branch cable 10 are required to be flatly inserted into the corresponding positions.

[0035] The grooves 18 and convex ridges 19 on the radial edges of the box-type connector are clean, dry and oil-free. On this basis, high-temperature resistant sealant is applied. It is a single-component type, waterproof, flame retardant, heat-resistant, and has good insulation properties (above 500 megohms). It has strong bonding strength and sealing effect, and focuses on sealing and bonding between metals. The working temperature is -4 to +1500℃, and can reach +1600℃ in a short time; close the other half of the arc-shaped connector box, align all the holes in place, and wipe off the excess glue immediately.

[0036] Aluminum metal box connector is used to install prefabricated branch connection section. Aluminum metal has high cost performance (compared with copper metal); small weight, specific gravity 2.7g / cm 3 (8.43g / cm3 for copper metal); the melting point of aluminum metal is 660℃, which is close to the temperature condition of 650℃-950℃ in the BS 6387 fireproof, waterproof and impactproof standard and is applicable. The thermal expansion coefficient (25℃ room temperature) is 0.0000236mm / ℃, the elastic modulus is 70Gpa, and the Poisson's ratio V=ε1 / ε=0.33 (the aluminum material will produce elongation or shortening deformation ε1 along the load direction, and shortening or elongation deformation ε will be produced in the direction perpendicular to the load). Plastic specific gravity is 0.9-2.2g / cm 3 ; Poor heat resistance and large thermal expansion coefficient; easy to burn and accompanied by the production of toxic gases.

[0037] The box-type connector is designed with two longitudinal semi-arc symmetrical parts, one end of which is the main cable inlet 12, the inner hole size is adapted to match the outer diameter of the cable outer sheath 7 (the total outer diameter of the cable), and the length is about 40mm.

[0038] The concave groove 14 is engaged with the convex clamp 15 on the aluminum metal sleeve 3. When the cable is installed vertically, the engagement device can prevent the cable from sagging due to its own weight, which can prevent the branch cable connection from being easily separated.

[0039] The other end is provided with a main cable outlet 16 and a branch cable outlet 17, with an appropriate distance between the two holes. The main cable outlet 16 has the same shape and size as the main cable inlet 12. The branch cable outlet 17 has the same shape as the main cable outlet 16, and its size is adapted to match the outer diameter of the aluminum metal sleeve 14 of the branch cable 10. The connected branch cable 10 is installed in the box-type connector between the two ends. A groove 18 is provided in the middle of the thickness of the radial peripheral edge of the first shell, with a width of 1-1.5mm and a depth of 1-1.5mm; a convex groove 19 is provided in the middle of the thickness of the radial peripheral edge of the second shell, with a width of 1-1.5mm and a height of 1-1.5mm; when the groove 18 and the convex ridge 19 are closed and assembled, they are connected and meshed.

Claims

1. An isolated prefabricated branch cable, characterized in that It comprises a main cable and a branch cable (10), one end of the branch cable (10) is connected to a conductor contact (11) of the main cable, and after the connection, a C-shaped crimping buckle (13) is sleeved on the outside of the conductor contact (11); The invention also comprises a box-type connector, which is sleeved on the outside of the branch cable (10) and the main cable, and is a split structure, consisting of a first shell and a second shell that are interlocked, a main cable inlet (12) is arranged at one end of the box-type connector, and a main cable outlet (16) and a branch cable outlet (17) are arranged at the other end, the main cable comprises a main cable inlet (8) and a main cable outlet (9), the main cable inlet (8) is arranged in the main cable inlet (12), and the main cable outlet (9) and the branch cable (10) are arranged at the main cable outlet (16) and the branch cable outlet (17), respectively; A concave groove (14) is provided on the inner wall of the main cable inlet (12), and a convex clamp (15) is provided on the main cable inlet (8), and the convex clamp (15) is clamped in the concave groove (14); The main cable and the branch cable (10) are composed of a twisted copper conductor (1), a mica tape insulation layer (2), an aluminum metal sheath (3), a toothed fireproof isolation sheath (4), a fireproof layer (5), a fireproof coating layer (6) and a halogen-free low-smoke outer sheath (7) from the inside to the outside.

2. The isolated prefabricated branch cable according to claim 1 is characterized in that A groove (18) is arranged at the edge of the first shell, and a convex ridge (19) is arranged on the second shell. The convex ridge (19) is arranged corresponding to the groove (18). When the first shell and the second shell are buckled, the convex ridge (19) is inserted into the groove (18).

3. The isolated prefabricated branch cable according to claim 2 is characterized in that After the first shell and the second shell are buckled together, a high temperature resistant sealant is applied to the joint.

4. The isolated prefabricated branch cable according to claim 1, characterized in that The inner wall edges of the first shell and the second shell are provided with fixing screw holes (20), and the first shell and the second shell are locked by bolts after being buckled.

5. The isolated prefabricated branch cable according to claim 4, characterized in that The fixing screw hole (20) comprises a non-threaded boring hole arranged on the first shell and a fine threaded hole arranged on the second shell, the non-threaded boring hole and the fine threaded hole correspond to each other, and the bolt passes through the non-threaded boring hole from outside to inside and is screwed with the fine threaded hole.

6. The isolated prefabricated branch cable according to claim 5, characterized in that There are 7 unthreaded boring holes and 7 fine thread holes respectively, and the fine thread holes are distributed in 2-2-3 from the line inlet to the line outlet.

7. An isolated prefabricated branch cable according to any one of claims 4 to 6, characterized in that The bolts are hexagon socket head screws.

8. The isolated prefabricated branch cable according to claim 1, characterized in that Two layers of mica tape and two layers of non-woven fabric are cross-wound on the outside of the conductor contact (11), and are coated with functional hot-melt sealant, which is baked by a blowtorch to shrink it to form an inner sealing package.

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